Off-shore wind turbines often comprise a pile, such as a mono-pile, which is anchored to the seabed, e.g. by being driven down into the seabed or by being held in place by a structure standing on the seabed. This mono-pile, possibly together with other structures affiliated with it, forms a foundation for a wind turbine tower to be erected thereon.
Often, the mono-pile is not connected directly to the tower since there might be a small angular difference in the axial direction between the tower sections and the mono-pile. Any angular difference is corrected by using a transition piece between the lower end of the tower and the top of the mono-pile. Using such a transition piece and positioning it correctly in order to vertically align the tower may take considerable effort and time and there is also a risk that the tower will have to be re-erected if the transition piece is incorrectly positioned, thus increasing the cost of off-shore wind turbine assembly.